This invention relates in general to optics, and more particularly, to optical sensing apparatus.
Infrared focal plane sensors sense objects by imaging infrared light reflected from the objects. Because different substances interact with light in different ways, and different atmospheric conditions can uniquely hinder the transmission of several wavelengths, it is desirable to image many different wavelengths or regions of the infrared electromagnetic spectrum.
In the following, the terms SWIR and LWIR light will be used. By SWIR it is meant short-wave infrared, or the region of the electromagnetic spectrum between the wavelengths of 1000 nm and 2000 nm. By LWIR is meant long-wave infrared, or the region of the electromagnetic spectrum between the wavelengths of 8000 nm and 117000 nm.
In the past, different sensors were used for different infrared wavelength regions and the images were fused for display. To do this, a large amount of signal processing was required.